Mai intai trebuie sa te autentifici.
Cod sursa(job #2374033)
| Utilizator | Data | 7 martie 2019 16:37:45 | |
|---|---|---|---|
| Problema | Arbori indexati binar | Scor | 100 |
| Compilator | cpp-64 | Status | done |
| Runda | Arhiva educationala | Marime | 1.19 kb |
#include <bits/stdc++.h>
using namespace std;
int aib[100010],n,logn;
void update(int poz,int s)
{
for(int i=poz;i<=n;i+=i&(-i)) aib[i]+=s;
}
int query(int poz)
{
int s=0;
for(int i=poz;i>0;i-=i&(-i)) s+=aib[i];
return s;
}
int caut_bin(int s)
{
int poz=0;
for(int i=logn;i>=0;i--)
if(poz+(1<<i)<=n && s>aib[poz+(1<<i)])
{
poz+=(1<<i);
s-=aib[poz];
}
return poz+1;
}
int main()
{
freopen("aib.in","r",stdin);
freopen("aib.out","w",stdout);
int m,x,t,y;
scanf("%d%d",&n,&m);
logn=0;
while((1<<logn)<=n) logn++;
logn--;
for(int i=1;i<=n;i++)
{
scanf("%d",&x);
update(i,x);
}
for(int i=1;i<=m;i++)
{
scanf("%d%d",&t,&x);
if(!t)
{
scanf("%d",&y);
update(x,y);
}
else if(t==1)
{
scanf("%d",&y);
printf("%d\n",query(y)-query(x-1));
}
else
{
int poz=caut_bin(x);
if(query(poz)==x) printf("%d\n",poz);
else printf("-1\n");
}
}
return 0;
}
